-- Thomson Constraints checker
-- Check wether picture is compatible with Thomson computers video modes
-- (8x1 cells with 2 colors out of 16 in each cell)
w,h=getpicturesize()
xcell = 8
selectlayer(1)
clearpicture(0)
selectlayer(0)
-- foreach grid cell
for y=0,h-1,1 do
for x1=0,w-1,xcell do
-- initialize our two colors for the cell, c1 is the color of the first
-- pixel, and we will look for c2 in the following pixels
c1 = getpicturepixel(x1,y)
c2 = -1
for x2=0,xcell-1,1 do
c = getpicturepixel(x1+x2, y)
-- is it a new color ?
if c ~= c1 and c ~= c2 then
if c2 == -1 then
-- C2 is free, we can use it for this new color
c2 = c
else
-- out of colors !
selectlayer(1)
putpicturepixel(x1+x2,y,17);
selectlayer(0)
end
end
end
end
end